Solder & Low-Melting Alloy SAC305
ISO 711 · also IEC A30C5
SAC305 is the industry-standard tin-silver-copper lead-free solder (IEC designation A30C5), with about 48 MPa tensile, 32 MPa yield, 35% elongation, 45 GPa elastic modulus and 15 HB.
Reference datasheet — SAC305 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
SAC305 tempers and conditions
SAC305 is supplied in 2 conditions, soft to hard.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Isothermally aged | Use for end-of-life / high-temperature reliability estimates, where IMC coarsening drops strength and stiffness. | 22 | 33 | 42 | 12 HB | 13.5 % IACS |
rapid cooling, fine Ag3Sn/Cu6Sn5 dispersion | Reference condition for joint-level design data straight off the reflow oven, before thermal ageing. | 40 | 55 | 25 | 17 HB | 13 % IACS |
Supply forms, finishes and certifications
Ways SAC305 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
BARDefault | Bar / ingot | Supply form |
FOIL | Rolled foil / strip | Supply form |
PREFORM | Preforms | Supply form |
SPHERE | Solder spheres / BGA balls | Supply form |
WIRE-CORED | Flux-cored wire | Supply form |
WIRE-SOLID | Solid wire / ribbon | Supply form |
PASTE | Solder paste | Printing process |
What is SAC305?
SAC305 is the industry-standard tin-silver-copper lead-free solder (IEC designation A30C5), with about 48 MPa tensile, 32 MPa yield, 35% elongation, 45 GPa elastic modulus and 15 HB. It is the default RoHS alloy for reflow paste, wave bar, cored wire, spheres, foil and preforms, and data is held for both reflowed and 150 °C-aged conditions. Practical limits are a 125 °C service ceiling, strength loss on thermal aging and silver cost; joints are also susceptible to tin whiskers and dendritic migration if flux residues remain. Binary Sn96.5Ag3.5 is the nearest copper-free alternative. SAC305 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 217°C (423 °F). SAC305 has a yield strength of 32 MPa (4.64 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 73% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 45 GPa (6.53 Msi).
What is SAC305 used for?
- reflow SMT soldering
- wave soldering
- solder paste/preforms
- RoHS-compliant electronics manufacturing
Advantages
- High electrical conductivity — 13 % IACS, better than 87% of solder & low-melting alloy grades
- Conducts heat well — 58 W/m·K (33.5 BTU/hr·ft·°F), better than 85% of solder & low-melting alloy grades
- Readily welded — 30/100, better than 83% of solder & low-melting alloy grades
- High service temperature — 125°C (257 °F), better than 80% of solder & low-melting alloy grades
Limitations
- Difficult to machine — 20/100, worse than 94% of solder & low-melting alloy grades
- High embodied carbon — 24 kg CO₂/kg, worse than 94% of solder & low-melting alloy grades
SAC305 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
SAC305 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 217°C (423 °F).
Mechanical11
SAC305 has a yield strength of 32 MPa (4.64 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 73% of solder & low-melting alloy grades. Elongation at break is 35% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
SAC305 is rated for continuous service to 125°C (257 °F). It conducts heat at 58 W/m·K (33.5 BTU/hr·ft·°F), better than 85% of solder & low-melting alloy grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
SAC305 conducts electricity at 13 % IACS, better than 87% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of SAC305 takes about 350 MJ of energy and emits 24 kg of CO₂ — more than 92% of solder & low-melting alloy grades. Typical recycled content is 25%.
Manufacturability6
SAC305's machinability is poor (20/100, worse than 94% of solder & low-melting alloy grades); weldability poor (30/100); formability excellent (90/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. SAC305 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SAC305
Is SAC305 easy to machine?
Rarely machined — extremely soft and gummy; use sharp positive-rake tools, high rake, kerosene-type lubricant, or simply stamp/shear preforms instead.
Can SAC305 be welded?
Not a welding alloy; joints are made by melting the solder itself — reflow peak 235–250 °C, wave pot 255–265 °C, with N2 helpful for wetting and dross control.
Can SAC305 be formed, bent or molded?
Casts to bar/ingot readily and draws to sub-0.3 mm wire or rolls to thin foil without intermediate anneal; atomized under inert gas for paste powder and BGA spheres.
SAC305 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| AgJ-STD-006 Sn96.5Ag3.0Cu0.5 (SAC305) | 2.9 – 3.2 | 3 |
| Cu | 0.4 – 0.6 | 0.5 |
| PbRoHS-compliant limit; many suppliers hold ≤0.05 | ≤ 0.07 | |
| Sbimpurity limit | ≤ 0.05 | |
| Biimpurity limit | ≤ 0.05 | |
| Feimpurity limit | ≤ 0.02 | |
| Asimpurity limit | ≤ 0.03 | |
| Cdimpurity limit | ≤ 0 | |
| Znimpurity limit | ≤ 0 | |
| Alimpurity limit | ≤ 0 | |
| Niimpurity limit (intentional Ni additions give SAC305+Ni variants) | ≤ 0.01 | |
| Snbalance, nominally 96.5 % | balance |
What surface finishes work on SAC305?
No coating normally applied; keep flux residues per IPC J-STD-001 cleanliness limits, and consider conformal coating or Ni/Bi-modified variants to suppress tin whiskers and dendritic migration.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy SAC305 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- 711
- Trade names
- IEC A30C5
- Also called
- J-STD-006 Sn96.5Ag3.0Cu0.5
How much does SAC305 cost?
SAC305 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SAC305 — frequently asked
What is SAC305 used for?
SAC305 is typically used for reflow SMT soldering, wave soldering, solder paste/preforms and roHS-compliant electronics manufacturing. In short: industry-standard lead-free solder; widest form availability; roHS default alloy.
What is the yield strength of SAC305?
SAC305 has a typical yield strength of 32 MPa (4.64 ksi) and a tensile strength of 48 MPa (6.96 ksi) — stronger than 73% of solder & low-melting alloy grades. Strength varies by condition: see the 2 listed tempers.
Is SAC305 easy to machine?
Not especially — machinability is rated poor (20/100, worse than 94% of solder & low-melting alloy grades). Rarely machined — extremely soft and gummy; use sharp positive-rake tools, high rake, kerosene-type lubricant, or simply stamp/shear preforms instead.
Can SAC305 be welded?
Not readily — weldability is rated poor (30/100). Not a welding alloy; joints are made by melting the solder itself — reflow peak 235–250 °C, wave pot 255–265 °C, with N2 helpful for wetting and dross control.
What surface finishes work on SAC305?
No coating normally applied; keep flux residues per IPC J-STD-001 cleanliness limits, and consider conformal coating or Ni/Bi-modified variants to suppress tin whiskers and dendritic migration.
Can SAC305 be formed, bent or molded?
Casts to bar/ingot readily and draws to sub-0.3 mm wire or rolls to thin foil without intermediate anneal; atomized under inert gas for paste powder and BGA spheres.
What is the maximum service temperature of SAC305?
SAC305 is rated for continuous use to about 125°C (257 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does SAC305 cost?
SAC305 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- IPC J-STD-006 — Requirements for Electronic Grade Solder Alloys — IPC (2013)
- IPC J-STD-005 / J-STD-004 — Solder paste and flux requirements — IPC (2012)
- IEC 61190-1-3 — Solder alloys (A30C5 designation) — IEC (2017)
- GB/T 20422 — SAC (China) (2018)
- SAC305 alloy and solder paste technical datasheets — Indium Corporation / AIM Solder / Kester / Alpha Assembly (2023)
- Properties of Lead-Free Solders / Pb-free solder property database — NIST (2002)
- Lead-Free Soldering — mechanical and reliability data compilations — Springer / IPC-9701 reliability literature (2011)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.